Fuel supply device

ABSTRACT

The fuel supply device includes a fuel pump configured to supply fuel from a fuel tank to an outside; a set plate set on an opening of the fuel tank and including a fuel chamber in which the fuel is stored; a fuel supply passage configured to supply the fuel chamber with a part of the fuel from the fuel pump; and a first electronic circuit disposed on the set plate. An outlet configured to discharge the fuel from the fuel chamber to the fuel tank is formed in the fuel chamber. A part of the first electronic circuit is exposed in the fuel chamber of the set plate.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Japanese Patent Application No.2012-081500 filed on Mar. 30, 2012, the contents of which are herebyincorporated by reference into the present application.

TECHNICAL FIELD

The technique disclosed in the present description relates to a fuelsupply device.

DESCRIPTION OF RELATED ART

Japanese Patent Application Publication No. 2008-215339 discloses a fuelsupply device that is provided with a set plate having a case body thatstores an electronic circuit and a fuel storage chamber that stores fuelfur cooling the electronic circuit. The case body and the cooling fuelstorage chamber are separated by a housing, and the electronic circuitis cooled by the fuel with the housing interposed.

SUMMARY

In Japanese Patent Application Publication No. 2008-215339, since theelectronic circuit is cooled by the fuel with the housing interposed,the efficiency of cooling the electronic circuit depends on the thermalconductivity of the housing. The present description provides a fuelsupply device that has a favorable efficiency of cooling the electroniccircuit

The present description discloses a technique related to a fuel supplydevice. The fuel supply device includes a fuel pump configured to supplyfuel from a fuel tank to an outside; as set plate set on an opening ofthe fuel tank and including a fuel chamber in which the fuel is stored;a fuel supply passage configured to supply the fuel chamber with a partof the fuel from the fuel pump; and a first electronic circuit disposedon the set plate. An outlet configured to discharge the fuel from thefuel Chamber to the fuel tank is formed in the fuel chamber. .A part ofthe first electronic circuit is exposed in the feel chamber of the setplate.

In the fuel supply device, the first electronic circuit is exposed inthe fuel chamber in which fuel for cooling the first electronic circuitcirculates. The fuel flows in direct contact with the first electroniccircuit to cool the first electronic circuit. Thus, high efficiency ofcooling the first electronic circuit can be Obtained regardless of thethermal conductivity of members such as a housing.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a longitudinal cross-sectional view of a fuel supply deviceaccording to a first embodiment;

FIG. 2 is an enlarged view near a first and a second electronic circuitof the fuel supply device shown in FIG. 1;

FIG. 3 is a cross-sectional view along line III-III of FIG. 2;

FIG. 4 is a cross-sectional view along line IV-IV of FIG. 2;

FIG. S is a view showing a fuel flowing direction in FIG. 2;

FIG. 6 is a view showing near a first and a second electronic circuit offuel supply device according to a second embodiment;

FIG. 7 is a cross-sectional view along line VII-VII of FIG. 6;

FIG. 8 is a view showing near a first and a second electronic circuit ofa fuel supply device according to a third embodiment;

FIG. 9 is a cross-sectional view along line IX-IX of FIG. 8;

FIG. 10 is a view showing near a first and a second electronic circuitof a fuel supply device according to a fourth embodiment;

FIG. 11 is a cross-sectional view along line XI-XI of FIG. ID;

FIG. 12 is a plan view of a body and a second casing according to amodification;

FIG. 13 is a perspective view showing a first and a second casingaccording to a modification;

FIG. 14 is a plan view of a body, a second casing, and the likeaccording to a modification; and

FIG. 15 is a view for explaining an electronic circuit provided in thesecond casing shown in FIG. 14.

DETAILED DESCRIPTION OF EMBODIMENT

In a fuel supply device disclosed in the present description, a fuelsupply passage may be connected to a bottom of a fuel chamber, and anoutlet may be adjacent to the fuel supply passage. Since fuel flowingfrom the outlet is delivered into a fuel tank along the adjacent fuelsupply passage, the sound of the fuel falling in the fuel tank isreduced, and the fed is reliably delivered into the reserve cup.

The fuel supply device disclosed in the present description may furtherinclude a controller configured to control an amount of fuel suppliedfrom the fuel supply passage in accordance with a calorific value of afirst electronic circuit. Control of increasing an amount of fuelsupplied when the first electronic circuit generates heat can beperformed, for example.

The fuel supply device disclosed in the present description may furtherinclude a second electronic circuit electrically connected to the firstelectronic circuit. The set plate may include a body including a firstcasing configured to store the first electronic circuit, a second casingconfigured to store the second electronic circuit, and a lid attached atan opening of the first casing. The fuel chamber may be formed in atleast a part of the first casing, the second casing may be positionedabove the first casing, and the second easing and the lid may beintegrally formed with resin. In this case, an air passage communicatingwith atmosphere is preferably formed between an upper surface of the lidand a lower surface of the second casing. When the lid attached at theopening of the first casing is formed with resin, fuel may permeatethrough the resin. Since the fuel permeating through the lid from theinside of the first casing is discharged to the atmosphere that passesthrough the air passage, the fuel can be suppressed from permeating intothe second casing in which the second electronic circuit vulnerable tofuel is stored. The air passage may serve as an inserting portion inwhich a fixing member configured to fix the second casing and the bodyis to be inserted. Heat generated by the first electronic circuit isprevented from being transmitted to the second electronic circuit.

In the fuel supply device disclosed in the present description, thesecond casing and a connector may be formed inside of a circumference ofthe body. For example, when the circumference of the body is circular ina plan view, the upper and lower surfaces of the second casing may havethe shape of a fan having an arc portion that follows the circumferenceof the body. Thus, the second casing can be disposed without protrudingfrom the circumference of the body.

In the fuel supply device disclosed in the present description, thefirst electronic circuit may be a pump controller configured to operatethe fuel pump. The pump controller is likely to generate heat and can beefficiently cooled by disposing the same in direct contact with fuel.Further, the first electronic circuit and may be a capacitance sensorconfigured to detect a property of the fuel. Since the pump controlleris in direct contact with the stirred fuel supplied from the fuel pump,the property of the fuel can be measured with high accuracy.

Representative, non-limiting, examples of the present invention will nowbe described in further detail with reference to the attached drawings.This detailed description is merely intended to teach a person of skillin the art further details for practicing preferred aspects of thepresent teachings and is not intended to limit the scope of theinvention. Furthermore, each of the additional features and teachingsdisclosed below may be utilized separately or in conjunction with otherfeatures and teachings to provide improved fuel supply devices.

Moreover, combinations of features and steps disclosed in the followingdetailed description may not be necessary to practice the invention inthe broadest sense, and are instead taught merely to particularlydescribe representative examples of the invention. Furthermore, variousfeatures of the above-described and below-described representativeexamples, as well as the various independent and dependent claims, mayhe combined in ways that are not specifically and explicitly enumeratedin order to provide additional useful embodiments of the presentteachings.

All features disclosed in the description and/or the claims are intendedto be disclosed separately and independently from each other for thepurpose of original written disclosure, as well as for the purpose ofrestricting the claimed subject matter, independent of the compositionsof the features in the embodiments and/or the claims. In addition, allvalue ranges or indications of groups of entities are intended todisclose every possible intermediate value or intermediate entity forthe purpose of original written disclosure, as well as for the purposeof restricting the claimed subject matter.

(First Embodiment)

A first embodiment that embodies the present invention will be describedwith reference to FIGS. 1 to 5. A fuel supply device I according to thisembodiment is attached to an automobile or the like and is used forsupplying fuel to an engine. As shown in FIG. 1, the fuel supply device1 includes a lid-shaped body 14 set on a fuel tank 12 and a fuel pump 22stored in the fuel tank 12. A fuel extracting pipe 14 b is formed on anupper surface of the body 14. The fuel extracting pipe 14 b is connectedto one end of a fuel supply pipe (not shown). The other end of the fuelsupply pipe is connected to the engine. The body 14 is circular in aplan view and is attached at an opening of the fuel tank 12.

A fuel supply portion 10 includes a reserve cup 18, a fuel pump 22, afuel filter 20, a suction filter 28, and a pressure regulator 30. Thereserve cup 18 is approximately cylindrical and has an open upper endand a bottom. The reserve cup 18 stores the fuel pump 22, the fuelfilter 20, the suction filter 28, and the pressure regulator 30 and isdisposed at the bottom of the fuel tank 12. The suction filter 28 isformed at the bottom of the reserve cup 18 and is positioned under thefuel pump 22. The pressure regulator 30 is funned at the bottom of thereserve cup 18. A first casing 40 of the body 14 and the pressureregulator 30 are connected by a pipe line 34.

The fuel pump 22 is stored in the reserve cup 18 so that an axial linethereof is vertical to the opening of the fuel tank 12 and a fueldischarge port 22 b is on the upper side and the fuel sucking port 22 ais on the lower side. The fuel discharge port 22 b is connected to thefuel filter 20 via a connection pipe 16 a. The fuel filter 20 isapproximately cylindrical and is arranged around the fuel pinup 22. Thefuel filter 20 is connected to the fuel extracting pipe 14 b via aconnection pipe 16 b. Moreover, the fuel filter 20 is connected to thepressure regulator 30. The pressure regulator 30 allows a part of fueldischarged from the fuel pump 22 to the fuel filter 20 to flow into apipe line 68 a to thereby regulate the pressure of the fuel flowing fromthe fuel filter 20 to the connection pipe 16 b. In this manner, thepressure of the fuel supplied to the engine is maintained to beconstant.

As shown in FIGS. 1 to 4, the first casing 40 that stores a firstelectronic circuit 60 is formed in the body 14. A second easing 42 thatstores a second electronic circuit 52 is positioned above the body 14. Aconnector 50 is formed in the second casing 42. That is, the body 14 andthe second casing 42 are examples of a “set plate” described in theclaims.

The first casing 40 includes an outer member 55 and an inner member 68.The first casing 40 includes a fuel supply passage 71, a fuel chamber72, and a fuel delivery passage 73 that are partitioned by the outermember 55 and the inner member 68.

The outer member 55 and the inner member 68 are disposed with a gaptherebetween. The inner member 68 includes the pipe line 68 a and acylindrical container 68 b having a bottom surface. The pipe line 68 ahas an upper end connected to the bottom surface of the container 68 band a lower end connected to the pipe line 34. The flow path inside thepipe line 68 a is the fuel supply passage 71. The inside of the outermember 55 is a fuel chamber, and a circuit storage portion 72 and a fueldelivery portion 73 are partitioned by the container 68 b. The inside ofthe container 68 b is the circuit storage portion 72, and the outside ofthe container 68 b is the fuel delivery portion 73. The entire firstelectronic circuit 60 is exposed to the circuit storage portion 70 ofthe fad chamber. The outer member 55 includes a pipe line 55 a and acylindrical container 55 b. The upper end of the container 55 b is open.The pipe line 55 a has an upper end connected to the bottom surface ofthe container 55 b. The pipe line 68 a is disposed inside the pipe line55 a The pipe line 55 a is sufficiently shorter than the pipe line 68 a,and an outlet 73 a at the lower and of the pipe line 55 a is open to theinside of the reserve cup 18 in the fuel tank 12, The pipe line 68 a isdisposed in and near the outlet 73 a, the outlet 73 a and a flow pathnear the outlet 73 a are partitioned by the outer surface of the pipeline 68 a and the inner surface of the pipe line 55 a. That is, theoutlet 73 a is adjacent to the outside of the heel supply passage 71.

The first electronic circuit 60 is a capacitance sensor. The firstelectronic circuit 60 includes a planar portion 57 and a pair ofelectrodes 58 a and 58 b formed on the front and rear surfaces of theplanar portion 57. The pair of electrodes 58 a and 58 b is a pair ofelectrodes formed on the front and rear surfaces so as to face eachother with a gap therebetween. The pair of electrodes 58 a and 58 b iselectrically connected to the second electronic circuit 52 by terminals59 a and 59 b, respectively. Since the first electronic circuit 60 is indirect contact with the fuel flowing inside the fuel chamber 72, theproperty (for example, quality, ethanol content, and the like) of thefuel can be examined by examining capacitance using the first electroniccircuit 60. The second electronic circuit 52 is a signal processingcircuit that processes electrical signals input from the firstelectronic circuit 60 and outputs processed signals to an externalcircuit via the connector 50. Although not shown in the figure, the fuelsupply device 1 includes a detector (for example, a thermistor or thelike) that detects a calorific value of the first electronic circuit 60.By controlling the fuel discharged from the fuel pump 22 according to adetection value detected by the detector, the amount of fuel suppliedfrom the pressure regulator 30 to the fuel chamber 72 can be controlled.In this manner, the amount of fuel supplied to the fuel chamber 72 isregulated according to the calorific value of the first electroniccircuit 60, and the first electronic circuit 60 is appropriately cooled.

The second casing 42 includes a housing 54 and a lid 53. The secondelectronic circuit 52 is disposed inside the housing 54, and the housing54 is sealed by the lid 53 funned on the upper surface of the housing54. The second electronic circuit 52 and the connector 50 areelectrically connected by a terminal 51.

The lower surface of the housing 54 is exposed to the inside of thefirst easing 40. The upper end of the planar portion 57 of the firstelectronic circuit 60 is fixed to the lower surface of the housing 54.The planar portion 57 extends downward from the lower surface of thehousing 54, and a lower end thereof is positioned in the circuit storageportion 72 of the fuel chamber of the first casing 40.

The body 14 and the outer member 55 are integrally formed with resin.The housing 54, the planar portion 57, and the connector 50 areintegrally funned with resin. The bottom of the housing 54 is fitted tothe inside of the outer member 55. The gap between the housing 54 andthe outer member 55 is sealed by a sealant 62. The bottom of the housing54 functions as a lid that is attached at the opening of the container55 b of the first casing 60. The upper end of the container 68 b of theinner member 6 excluding a portion in which the passage 72 a is formedis bonded to the lower surface of the housing 54.

The operation of the fuel supply device 1 will be described. When poweris supplied to the fuel pump 22 from an external power source, the fuelpump 22 operates. When the fuel pump 22 operates, the fuel in thereserve cup 18 is sucked and filtered by the suction filter 28 and issucked into the fuel pump 22 from the fuel sucking port 22 a. The fuelsucked into the fuel pump 22 is pressurized and is discharged from thefuel discharge port 22 b. The fuel discharged from the fuel pump 22 isdelivered to the fuel filter 20 and is filtered again. The pressure ofthe fuel filtered by the fuel filter 20 is regulated to appropriatepressure according to an operation state of the engine by the pressureregulator 30. The pressure-regulated fuel is delivered to the enginefrom the fuel extracting pipe 14 b.

On the other hand, the fuel returning from the pressure regulator 30 isdelivered to the DA supply passage 71 in the pipe line 68 a. FIG. 5shows the flow of fuel flowing through the fuel supply passage 71, thecircuit steerage portion 72, and the fuel delivery portion 73 by arrows.The fuel delivered from the pressure regulator 30 to the fuel supplypassage 71 passes through a connection portion between the pipe line 68a and the container 68 b and is then delivered into the circuit storageportion 72 of the fuel chamber. The first electronic circuit 60 isdisposed in the circuit storage portion 72 in an exposed state, and thefirst electronic circuit 60 is in contact with fuel and cooled by fuel.Since the first electronic circuit 60 is in direct contact with fuel,the first electronic circuit 60 is efficiently cooled. Since the fuelthat is discharged from the fuel pump 22 and is stirred is in contactwith the first electronic circuit 60, the first electronic circuit 60can detect fuel properties with high accuracy. That is, when the fuel inthe fuel tank 12 is configured to be in contact with the firstelectronic circuit 60 (that is, a capacitance sensor), if the fuel isseparated within the fuel tank 12, the first electronic circuit 60cannot accurately detect fuel properties. On the other hand, accordingto the configuration of this embodiment, since the first electroniccircuit 60 is in contact with the fuel that is discharged from the fuelpump 22 and is stirred, the above problem does not occur, and the fuelproperties can be detected with high accuracy. The container 68 b storesan amount of fuel necessary for the first electronic circuit 60 to allowthe first electronic circuit 60 to be reliably in contact with the fuel.Moreover, when the pressure regulator 30 or a check valve (not shown)formed upstream the container 68 b is closed, the fuel stored in thecontainer 68 b is maintained even when the fuel pump 22 is stopped.

After that, the fuel passes through the passage 72 a above the container68 b and flows into the fuel delivery portion 73 between the container68 b and the container 55 b. The fuel passes through the fuel deliveryportion 73 and is discharged from the outlet 73 a to the fuel tank 12.Since the outlet 73 a is adjacent to the outer surface of the pipe line68 a that partitions the fuel supply passage 71, the fuel reliablyreturns into the reserve cup 18 in the fuel tank 12 along the outersurfaces of the pipe line 68 a and the pipe line 34 connected to thepipe tine 68 a, As shown in FIG. 1, since the pipe fine 34 extends up tothe pressure regulator 30 formed under the fuel tank 12, the fueldischarged from the outlet 73 a can be suppressed from falling on thesurface of the fuel stored in the reserve cup 18 from the outlet 73 a,and the generation of the sound of the falling fuel can be suppressed.

(Second Embodiment)

A fuel supply device according to a second embodiment is different fromthe fuel supply device according to the first embodiment in terms of theconfiguration of the first casing.

As shown in FIGS. 6 and 7, a first casing 140 includes an outer member155, a pipe line 168 a, and a planar portion 168 h. The outer member 155includes a semi-circular pipe line 155 a of which the cross-section ofthe flow path has an approximately semi-circular shape and a cylindricalcontainer 155 b having a bottom surface. The upper end of the container155 b is open. The semi-circular pipe line 155 a is bonded to a sidesurface of the pipe line 168 a on a side where the semi-circular pipeline 155 a is chipped in an approximately semi-circular shape. The upperends of the semi-circular pipe line 155 a and the pipe line 168 a areconnected to the bottom surface of the container 155 h. The lower end ofthe pipe line 168 a is connected to the pipe line 34. The inner flowpath of the pipe line 168 a is the fuel supply passage 171. The planarportion 168 b is disposed at such a position that the planar portion 168b passes above the semi-circular pipe line 155 a and the pipe line 168 aand partitions the container 155 b. The inside of the container 155 b isa fuel chamber and is separated by the planar portion 168 b into acircuit storage portion 172 connected to the pipe line 168 a and a fueldelivery portion 173 connected to the semi-circular pipe line 155 a. Thecircuit storage portion 172 and the fuel delivery portion 173communicate with each other in a passage 172 a that is above the planarportion 168 b. The fuel delivery portion 173 is connected to an outlet173 a that is at the lower end of the semi-circular pipe line 155 a.Similarly to FIG. 1, the outlet 173 a is open to the inside of thereserve cup 18 in the fuel tank 12. The outlet 173 a and the vicinitythereof are formed of the inner surface of the semi-circular pipe line155 a and a part of the outer surface of the pipe line 168 a and areadjacent to a part of the outer surface of the fuel supply passage 171.

The body 14, the outer member 155, the pipe line 168 a, and the planarportion 168 b are integrally formed with resin. The housing 54 and theconnector 50 are integrally formed with resin.

A first electronic circuit 160 is disposed in the circuit storageportion 172 in an exposed state. Since the specific configuration of thefirst electronic circuit 160 is the same as the first electronic circuit60, detailed description thereof will not he provided. Since the otherconfiguration of the fuel supply device according to the secondembodiment is the same as the first embodiment, description thereof willnot be provided.

According to the second embodiment, the same operational effects as thefirst embodiment can be obtained. That is, since the first electroniccircuit 160 is exposed to the inside of the circuit storage portion 172of the fuel chamber and is in direct contact with fuel, the firstelectronic circuit 160 is efficiently cooled. Moreover, the outlet 173 ais adjacent to a part of the outer surface of the pipe line 168 a thatpartitions the fuel supply passage 171. Thus, the fuel reliably returnsinto the reserve cup 18 in the fuel tank 12 along the outer surfaces ofthe pipe line 168 a and the pipe line 34, and the generation of thesound of the fuel falling when the fuel is delivered can be suppressed.Further, since the first electronic circuit 160 is in contact with thefuel that is discharged from the fuel pump 22 and is stirred, the firstelectronic circuit 160 can detect fuel properties with high accuracy.

(Third Embodiment)

A fuel supply device according to a third embodiment is different fromthe fuel supply device according to the first embodiment in terms of theconfiguration of the first and second casings and the first electroniccircuit.

As shown in FIGS. 8 and 9, a first casing 240 includes an outer member255, an inner member 268, and a lid 254 d. A second casing 242 includesa lid 253, a housing 254 a, and connecting portions 254 b and 254 c thatconnect the housing 254 a and the lid 254 d. The lower surface of thehousing 254 a and the upper surface of the lid 254 d are separated, andan air passage 275 communicating with atmosphere is formed between theupper and lower surfaces. The air passage 275 is surrounded by the lowersurface of the housing 254 a, the upper surface of the lid 254 d, andthe connecting portions 254 b and 254 e. In FIG. 9, for betterunderstanding of the configuration of the first casing 240, the lid 254d and the first electronic circuit 260 appearing on the IX-IXcross-section shown in FIG. 8 are not depicted.

The inner member 268 includes a pipe line 268 a and a housing-shapedcontainer 268 b having a bottom surface. The upper end of the pipe line268 a is connected to the bottom surface of the container 268 b and thelower end thereof is connected to the pipe line 34. The outer member 255includes a pipe line 255 a and a housing-shaped container 255 b. Theupper end of the container 255 b is aspen. The container 268 b is bondedto the container 255 b in the y-axis direction shown in FIG. 8 and isbonded to the lid 254 d in the positive (upward) z-axis direction. Thecontainer 268 b is separated from the lid 264 d in a passage 272 a thatis formed in a part of the upper portion of the container 268 b. Theupper end of the pipe line 255 a is connected to the bottom surface ofthe container 255 b. The pipe line 268 a is disposed inside the pipeline 255 a.

The flow path inside the pipe line 268 a is the fuel supply passage 271.The inside of the outer member 255 is a fuel chamber and is partitionedinto a circuit storage portion 272 and a fuel delivery portion 273 bythe container 268 b. The inside of the container 268 b is the circuitstorage portion 272, and the outside of the container 268 b is the fueldelivery portion 273. The first electronic circuit 260 is stored in thefirst easing 240. The first electronic circuit 260 is fixed so that theplanar direction thereof is parallel to the lower surface of the lid 254d, and the lower surface thereof is exposed to the inside of the circuitstorage portion 272. The first electronic circuit 260 is a heatgenerating portion of a pump controller that operates the fuel pump 22.The second electronic circuit 252 is stored in the housing 254 a of thesecond casing 242 and is sealed by the lid 253. The second electroniccircuit 252 is a signal processing circuit of the pump controllersimilarly to the first embodiment and the like. The first and secondelectronic circuits 260 and 252 are electrically connected by a terminal259 that extends from the second electronic circuit 252 and passesthrough the housing 254 a, the connecting portion 254 b, and the lid 254d.

The pipe line 255 a is sufficiently shorter than the pipe line 268 a,and the lower end of the pipe line 255 a is open to the inside of thereserve cup 18 in the fuel tank 12 similarly to FIG. 1. The pipe line268 a is disposed in and near the outlet 273 a, and the outlet 273 a anda flow path near the outlet 273 a are partitioned by the out surface ofthe pipe line 268 a and the inner surface of the pipe line 255 a. Thatis, the outlet 273 a is adjacent to the outside of the fuel supplypassage 271.

The body 214 and the outer member 255 are integrally formed with resin.The housing 254 a, the connecting portions 254 b and 254 c, the lid 254d, and the connector 50 are integrally formed with resin. The lid 254 dis fitted to the inside of the outer member 255. The gap between the lid254 d and the outer member 255 is sealed by a sealant 262. The lid 254 dis attached at an opening of the container 255 b of the first casing240. The upper end of the container 268 b of the inner member 26$excluding a portion in which the passage 272 a is formed is bonded tothe lower surface of the lid 254 d. Since the other configuration of thefuel supply device according to the third embodiment is the same as thefirst embodiment, description thereof will not be provided.

According to the third embodiment, the same operational effect as thefirst embodiment can be obtained. That is, since the first electroniccircuit 260 is exposed to the inside of the circuit storage portion 272of the fuel chamber and is in direct contact with fuel, the firstelectronic circuit 260 is efficiently cooled. Moreover, the outlet 273 ais adjacent to the outer surface of the pipe line 268 a that partitionsthe fuel supply passage 271. Thus, the fuel reliably returns into thereserve cup 18 in the fuel tank 12 along the outer surfaces of the pipeline 268 a and the pipe line 34, and the generation of the sound of thefuel falling when the fuel is delivered can be suppressed. Further,since the first electronic circuit 260 is the heat generating portion ofthe pump controller, the pump controller is likely to generate heat.Since the first electronic circuit 260 that is likely to generate heatis in contact with the fuel, the first electronic circuit 260 can beefficiently cooled.

In the third embodiment, the air passage 275 communicating withatmosphere is formed between the upper surface of the lid 245 d attachedat the opening of the first casing 240 and the lower surface of thehousing 254 a of the second casing 242. Since the lid 245 d is formedwith resin, a concern may occur that fuel may permeate into the secondcasing 242 through the lid 254 d from the inside of the first casing240. According to the third embodiment, the air passage 275 is formedbetween the upper surface of the lid 245 d and the lower surface of thehousing 254 a of the second casing 242. Thus, even when the fuel in thefirst easing 240 permeates through the lid 245 d, the fuel diffuses intothe atmosphere through the air passage 275, and the fuel is suppressedfrom further permeating into the second casing 242. That is, the fuel issuppressed from permeating into the second casing in which the secondelectronic circuit vulnerable to fuel is stored.

The air passage 275 may serve as an inserting portion in which a fixingmember fur fixing the second casing 242 and the body 214 is to heinserted. For example, an engagement portion that engages with thefixing member may be formed on a side of the connecting portions 254 band 254 c closer to the air passage 275, the fixing member may beinserted in the air passage 275, and the engagement portion on the airpassage 275 may be engaged with the engagement portion on the fixingmember, whereby the second casing 242 and the body 214 are fixed.

(Fourth Embodiment)

A fuel supply device according to a fourth embodiment is different fromthe fuel supply device according to the third embodiment in terms of theconfiguration of the first casing.

As shown in FIGS. 10 and 11, a first casing 340 includes an outer member355, a pipe line 368 a, and a planar portion 368 b. The outer member 355includes an approximately semi-circular pipe line 355 a and ahousing-shaped container 355 b. The upper end of the container 355 b isopen. The semi-circular pipe line 355 a is bonded to a side surface ofthe pipe line 368 a on a side where the semi-circular pipe line 355 a ischipped in an approximately semi-circular shape. The semi-circular pipeline 355 a and the pipe line 368 a have upper ends connected to thebottom surface of the container 355 b and are disposed closer to thenegative y-axis side than the center in the y-axis direction of thebottom surface. The lower end of the pipe line 368 a is connected to thepipe line 34. The flow path inside the pipe line 368 a is a fuel supplypassage 371. The planar portion 368 b is disposed at such a positionthat the planar portion 368 b passes above the semi-circular pipe line355 a and the pipe line 368 a and partitions the container 355 b. Theinside of the container 355 b is a fuel chamber and is separated by theplanar portion 368 b into a circuit storage portion 372 connected to thepipe line 368 a and a fuel delivery portion 373 connected to thesemi-circular pipe line 355 a. A passage 372 a is formed near and abovean end of the planar portion 368 b in the positive y-axis direction, andthe circuit storage portion 372 and the fuel delivery portion 373communicate with each other through the passage 372 a. The fuel deliveryportion 373 is further connected to an outlet 373 a that is at the lowerend of the semi-circular pipe line 355 a. The outlet 373 a is open tothe inside of the reserve cup 18 in the fuel tank 12 similarly toFIG. 1. The outlet 373 a and the vicinity thereof are formed of theinner surface of the semi-circular pipe line 355 a and a part of theouter surface of the pipe line 368 a and are adjacent to a part of theouter surface of the fuel supply passage 371.

The body 214, the outer member 355, the pipe line 368 a, and the planarportion 368 b are integrally formed with resin. The housing 254 a, theconnecting portions 254 b and 254 c, the lid 254 d, and the connector 50are integrally formed with resin. Since the other configuration of thefuel supply device according to the fourth embodiment is the same as thethird embodiment, description thereof will not be provided.

In the fourth embodiment, the same operational effect as the firstembodiment can be obtained. That is, since the first electronic circuit260 is exposed to the inside of the circuit storage portion 372 of thefuel chamber and is in direct contact with fuel, the first electroniccircuit 260 is efficiently cooled. Moreover, the outlet 373 a isadjacent to a part of the outer surface of the pipe line 368 a thatpartitions the fuel supply passage 371. Thus, the fuel reliably returnsinto the reserve cup 18 in the fuel tank 12 along the outer surfaces ofthe pipe line 368 a and the pipe line 34, and the generation of thesound of the fuel falling when the fuel is delivered can be suppressed.

Moreover, since the same air passage 275 as the third embodiment isformed, the fuel can be suppressed from permeating into the secondcasing 242 from the inside of the first casing 340. Further, since thefirst electronic circuit 260 is the heat generating portion of the pumpcontroller, the pump controller is likely to generate heat. Since thefirst electronic circuit 260 that is likely to generate heat is incontact with the fuel, the fast electronic circuit 260 can beefficiently cooled. Furthermore, the heat generated by the firstelectronic circuit can be prevented from being transmitted to the secondelectronic circuit.

(Modification)

The second casing and the connector are preferably formed inside of thecircumference of the body. For example, when the body is circular in aplan view, the upper and lower surfaces of the second casing may havethe shape of a fan having an arc portion that follows the circumferenceof the body. As shown in FIGS. 12 and 13, the upper and lower surfacesof a second casing 542 are fan-shaped in a plan view, and an arc portion542 a of the second casing 542 follows a circumference 514 a of acircular body 514. A first casing 540 extends from the fare-shaped lowersurface of the second casing 542, and a connector 550 extends from aside surface that is connected to a straight line portion of the fanshape of the second casing 542. The second casing 542 may be disposed onthe upper surface of the body 514 without protruding from thecircumference of the body 514.

As shown in FIG. 14, two second casings 642 a and 642 b of which theupper and lower surfaces have a fan shape having a central angle of 90°may be disposed above a circular body 614 in a plan view. A secondelectronic circuit stored in the second casing 642 a is a pumpcontroller. A second electronic circuit stored in the second casing 642b is a capacitance fuel sensor. Moreover, the second casings 642 a and642 b may be disposed adjacent to each other, and a fuel extracting pipe614 b and a fuel returning pipe 614 c may be formed in an upper portionof the body 614 where the second casings 642 a and 642 b are not fowled.As shown in FIG. 15, a pump controller (FPC) stored in the second casing642 a controls a fuel pump (EFP) in response to electrical signals froman external circuit (not shown). Moreover, a part of the fuel suppliedfrom the fuel pump is supplied to the capacitance fuel sensor stored inthe second casing 642 b, and electrical signals that indicate themeasured fuel quality are output to the external circuit (not shown).The external circuit outputs signals for controlling the pump controllerbased on various types of information that indicate an engine operationstate. Since constituent elements in FIG. 15 denoted by the samereference numerals as FIG. I represent the same configuration as FIG. 1,description thereof will not be provided.

What is claimed is:
 1. A fuel supply device comprising: a fuel pumpconfigured to supply fuel from a fuel tank to an outside; a set plateset on an opening of the fuel tank and including a fuel chamber in whichthe fuel is stored; a fuel supply passage configured to supply the fuelchamber with a part of the fuel from the fuel pump; and a firstelectronic circuit disposed on the set plate, wherein an outletconfigured to discharge the fuel from the fuel chamber to the fuel tankis formed in the fuel chamber, and a part of the first electroniccircuit is exposed in the fuel chamber of the set plate.
 2. The fuelsupply device of claim 1, wherein the fuel supply passage is connectedto a bottom of the fuel chamber, and the outlet is adjacent to the fuelsupply passage.
 3. The fuel supply device of claim 1, further comprisinga controller configured to control an amount of fuel supplied from thefuel supply passage in accordance with a calorific value of the firstelectronic circuit.
 4. The fuel supply device of claim 1 furthercomprising a second electronic circuit electrically connected to thefirst electronic circuit, wherein the set plate includes: a bodyincluding a first casing configured to store the first electroniccircuit, a second casing configured to store the second electroniccircuit, and a lid attached at an opening of the first casing, the fuelchamber is formed in at least a part of the first casing, the secondcasing is positioned above the first casing, the second casing and thelid are integrally formed with resin, and an air passage communicatingwith atmosphere is funned between an upper surface of the lid and alower surface of the second casing.
 5. The fuel supply device of claim4, wherein the air passage serves as an inserting portion in which afixing member configured to fix the second casing and the body is to beinserted.
 6. The fuel supply device of claim 4, wherein the secondcasing and a connector are for d inside of a circumference of the body.7. The fuel supply device of claim 1, wherein the first electroniccircuit is a pump controller configured to operate the fuel pump.
 8. Thefuel supply device of claim 1, wherein the first electronic circuit is acapacitance sensor configured to detect a property of the fuel.